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核心提示：ntel Corporation PRoprietary InformationCopyright (c) 1995 Intel CorporationThis listing is supplied under the terms of a license agreement withIntel Corporatio

　　ntel Corporation PRoprietary Information
Copyright (c) 1995 Intel Corporation

This listing is supplied under the terms of a license agreement with
Intel Corporation and may not be used, copied, nor disclosed except in
accordance with the terms of that agreeement.

Module Name:

select.c

Abstract:

This module contains the “select“ entry points from the winsock
API. The following functions aare contained in this module.

select()
WSAEventSelect()
WSAAsyncSelect()
__WSAFDIsSet()

Author:

Dirk Brandewie dirk@mink.intel.com 14-06-1995

Revision History:

22-Aug-1995 dirk@mink.intel.com
Cleanup after code review. Moved includes to precomp.h

16-Aug-1995 dirk@mink.intel.com
Added implementation of __WSAFDIsSet

--*/
#include “precomp.h“

int WSAAPI
select (
IN int nfds,
IN OUT fd_set FAR *readfds,
IN OUT fd_set FAR *writefds,
IN OUT fd_set FAR *exceptfds,
IN const strUCt timeval FAR *timeout
)
/*++
Routine Description:

Determine the status of one or more sockets, waiting if necessary.

Arguments:

nfds - This argument is ignored and included only for the sake of
compatibility.

readfds - An optional pointer to a set of sockets to be checked
for readability.

writefds - An optional pointer to a set of sockets to be checked
for writability.

exceptfds - An optional pointer to a set of sockets to be checked
for errors.

timeout - The maximum time for select() to wait, or NULL for
blocking Operation.

Returns:
select() returns the total number of descriptors which are ready
and contained in the fd_set structures, 0 if the time limit
eXPired, or SOCKET_ERROR if an error occurred. If the return
value is SOCKET_ERROR, The error code is stored with
SetLastError().
--*/
{
INT ReturnValue;
INT ErrorCode;
PDPROVIDER Provider;
PDSOCKET Socket;
SOCKET SocketID;
BOOL FoundSocket=FALSE;

ErrorCode = TURBO_PROLOG();

if (ErrorCode == ERROR_SUCCESS) {

__try {
// Look for a socket in the three fd_sets handed in. The first
// socket found will be used to select the service provider to
// service this call
if (readfds && readfds->fd_count)
{
SocketID = readfds->fd_array[0];
FoundSocket = TRUE;
} //if

if (!FoundSocket && writefds && writefds->fd_count )
{
SocketID = writefds->fd_array[0];
FoundSocket = TRUE;
} //if

if (!FoundSocket && exceptfds && exceptfds->fd_count )
{
SocketID = exceptfds->fd_array[0];
FoundSocket = TRUE;
} //if
}
__except (WS2_EXCEPTION_FILTER()) {
ErrorCode = WSAEFAULT;
goto ReturnError;
}

if (FoundSocket) {
Socket = DSOCKET::GetCountedDSocketFromSocket(SocketID);
if(Socket != NULL){
Provider = Socket->GetDProvider();
ReturnValue = Provider->WSPSelect(
nfds,
readfds,
writefds,
exceptfds,
timeout,
&ErrorCode);
Socket->DropDSocketReference();
if (ReturnValue!=SOCKET_ERROR)
return ReturnValue;

assert (ErrorCode!=NO_ERROR);
if (ErrorCode==NO_ERROR)
ErrorCode = WSASYSCALLFAILURE;

} //if
else {
ErrorCode = WSAENOTSOCK;
}
} //if
else {
ErrorCode = WSAEINVAL;
} //else
}

ReturnError:
SetLastError(ErrorCode);
return(SOCKET_ERROR);
} //select

int WSAAPI
WSAEventSelect(
IN SOCKET s,
IN WSAEVENT hEventObject,
IN long lNetworkEvents
)
/*++
Routine Description:

Specify an event object to be associated with the supplied set of
FD_XXX network events.

Arguments:

s - A descriptor identifying the socket.

hEventObject - A handle identifying the event object to be
associated with the supplied set of FD_XXX network
events.

lNetworkEvents - A bitmask which specifies the combination of
FD_XXX network events in which the application
has interest.

Returns:
Zero on success else SOCKET_Error. The error code is stored with
SetLastError().
--*/
{
INT ReturnValue;
INT ErrorCode;
PDPROVIDER Provider;
PDSOCKET Socket;

ErrorCode = TURBO_PROLOG();

if (ErrorCode == ERROR_SUCCESS) {
Socket = DSOCKET::GetCountedDSocketFromSocket(s);
if(Socket != NULL){
Provider = Socket->GetDProvider();
ReturnValue = Provider->WSPEventSelect(
s,
hEventObject,
lNetworkEvents,
&ErrorCode);
Socket->DropDSocketReference();
if (ReturnValue==ERROR_SUCCESS)
return ReturnValue;
assert (ErrorCode!=NO_ERROR);
if (ErrorCode==NO_ERROR)
ErrorCode = WSASYSCALLFAILURE;
}
else {
ErrorCode = WSAENOTSOCK;
}
}

SetLastError(ErrorCode);
return SOCKET_ERROR;
} //WSAEventSelect

int WSAAPI
WSAAsyncSelect(
IN SOCKET s,
IN HWND hWnd,
IN u_int wMsg,
IN long lEvent
)
/*++
Routine Description:

Request event notification for a socket.

Arguments:

s - A descriptor identifying the socket for which event notification is
required.

hWnd - A handle identifying the window which should receive a message when
a network event occurs.

wMsg - The message to be received when a network event occurs.

lEvent - A bitmask which specifies a combination of network events in which
the application is interested.

Returns:
The return value is 0 if the application‘s declaration of interest in the
network event set was successful. Otherwise the value SOCKET_ERROR is
returned, and a specific error number may be retrieved by calling
WSAGetLastError().
--*/
{
INT ReturnValue;
INT ErrorCode;
PDPROVIDER Provider;
PDSOCKET Socket;

ErrorCode = TURBO_PROLOG();

if (ErrorCode == ERROR_SUCCESS) {
Socket = DSOCKET::GetCountedDSocketFromSocket(s);
if(Socket != NULL){
Provider = Socket->GetDProvider();
ReturnValue = Provider->WSPAsyncSelect(
s,
hWnd,
wMsg,
lEvent,
&ErrorCode);
Socket->DropDSocketReference();
if (ReturnValue==ERROR_SUCCESS)
return ReturnValue;
assert (ErrorCode!=NO_ERROR);
if (ErrorCode==NO_ERROR)
ErrorCode = WSASYSCALLFAILURE;
}
else {
ErrorCode = WSAENOTSOCK;
}
}

SetLastError(ErrorCode);
return SOCKET_ERROR;
} //WSAAsyncSelect

int FAR PASCAL
__WSAFDIsSet(
SOCKET fd,
fd_set FAR *set)
/*++
Routine Description:

Determines if a specific socket is a contained in an FD_SET.

Arguments:

s - A descriptor identifying the socket.

set - A pointer to an FD_SET.
Returns:

Returns TRUE if socket s is a member of set, otherwise FALSE.

--*/
{
int i = set->fd_count; // index into FD_SET
int rc=FALSE; // user return code

while (i--){
if (set->fd_array[i] == fd) {
rc = TRUE;
} //if
} //while
return (rc);
} // __WSAFDIsSet

int FAR PASCAL
WPUFDIsSet(
SOCKET fd,
fd_set FAR *set)
/*++
Routine Description:

Determines if a specific socket is a contained in an FD_SET.

Arguments:

s - A descriptor identifying the socket.

set - A pointer to an FD_SET.
Returns:

Returns TRUE if socket s is a member of set, otherwise FALSE.

--*/
{
int return_value;

return_value = __WSAFDIsSet(
fd,
set
);
return(return_value);
} // WPUFDIsSet